Capitalization - Additional Information (Detail) - USD ($)			3 Months Ended
	Mar. 12, 2019	Nov. 01, 2017	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Schedule of Capitalization, Equity [Line Items]
Common stock, par value			$ 0.00001		$ 0.00001
Proceeds from issue of common stock			$ 40,000	$ 6,000
Common stock, shares outstanding			14,443,569		14,428,916
Preferred stock, shares outstanding			0		0
ATM Facilty [Member]
Schedule of Capitalization, Equity [Line Items]
Agreed sale price of shares	$ 50,000,000
Compensation entitled as percentage of gross proceeds of shares sold under ATM Facility	3.00%
Stock Purchase Agreement [Member]
Schedule of Capitalization, Equity [Line Items]
Number of additional shares issued and sold		70,000
Common stock, par value		$ 0.00001
Shares issued, price per share		$ 11.00
Proceeds from issue of common stock		$ 770,000
Transaction closing date		Nov. 02, 2017